Shelving and systems for supporting shelves are used in many applications, such as warehousing and storage operations, manufacturing, retail stores, and home use such as in home workshops. Many shelving support systems are designed to rest on the floor, or to be attached to the walls. However, these methods of support have a number of disadvantages. Floor-supported shelf systems may mar the floor or require the modification of the floor surfaces to accommodate their placement. For example, shelf supports placed on wood floors may scratch the wood, whereas on carpet they may crush the carpet material. In some instances special mounting modifications may be needed to adequately support shelves needing a rigid footing on an otherwise relatively soft, carpeted surface. Similarly, wall-supported shelf systems may require wall surfaces to be modified, or the wall surface may be damaged by the shelves or their supports. For example, holes might need to be drilled to support shelf brackets, and wall finishes such as plaster can be damaged by contact with the shelf supports or the shelves themselves. Floor-supported shelves may have an undesirably large footprint, and the lower shelves may be largely invisible to people standing nearby. Some walls may not be strong enough to support the weight of cantilevered shelves and their contents, or it may be desired to locate the shelves away from any walls capable of bearing a weight load.
Supporting shelves from an overhead point of attachment has also been provided in the prior art, and this method of hanging shelves offers certain advantages. By suspending a shelf system from overhead, available floor area is expanded and ease of access may be enhanced. Visibility of the contents of the shelves is improved, as the shelves can be placed at convenient eye level without wasting space on shelves at lower positions that are harder to see without effort, and the placement of which may serve to hide items on the shelves from view or in shadow. Also, shelves mounted from an overhead point of attachment are much less likely to topple over than are shelf assemblies resting on the floor, possibly causing damage or injury, when the shelves are subjected to a lateral force such as in an earthquake or even from people leaning or pushing on the shelf assembly. Shelves mounted from overhead may even be safer than wall-mounted shelves in regards to seismic safety, as the weight is suspended from directly overhead so there is no leverage effect putting added stress on the point of attachment as is the case with wall mounting.
A number of approaches have been taken to providing systems for hanging shelves from overhead support structures such as ceiling joists. For example, U.S. Pat. No. 1,566,551 proposes a shelving support system comprising a crossbar with pendant hanging devices, one at each end of the crossbar, the pendant fastening devices having rests on which the shelf boards are supported, the crossbar being attached to an overhead support. However in this system the vertical positions of the various shelves are defined by where the rests are located on the pendant hanging devices and are not adjustable. Also, assembly of the unit is somewhat involved, and no provisions are made for tightening the structure when weight and wear have tended to loosen the fasteners.
U.S. Pat. No. 6,435,105 describes a suspended storage structure comprising wire shelves that are attached to a frame comprising drilled metal straps which are fastened together with nuts and bolts. While providing for a degree of adjustability, the system is rather unattractive constructed as it is of metal strapping that while perhaps suitable for a manufacturing environment would be inappropriate in an environment in which appearance is important.
Other systems have made use of flexible suspension members such as chains, which provide for suspending shelves without the need for retightening fasteners, since usage and the weight suspended tends to loosen them over time. U.S. Pat. No. 4,061,092 proposes using chains which are hung from an overhead support member to which shelf brackets are attached upon which the shelves rest. While relatively easy to install, this system again lacks aesthetic appeal in that the metal chains and shelf brackets are exposed to view, which is undesirable in an application where appearance is a factor. Also, use of chains provides no rigidity to the system, making it very prone to swinging motion in response to a lateral force.
U.S. Pat. No. 6,116,164 describes a suspended shelving apparatus wherein shelves can easily be repositioned, but the chains themselves are still visible, not adding to the visual appeal of the display. Again, shelves suspended from chains are highly prone to motion, swinging back and forth in response to a push on a shelf, due to the complete lack of rigidity of the chains.
Therefore, there is a need for supports and support systems for hanging shelving that can suspend one or more shelves from an overhead point of attachment, provides an attractive appearance with a finished look as would be suitable for shelving in any application where an attractive, finished appearance is desirable, and provides a support for shelves that is at least somewhat more rigid than chains are.